Mbx821 002b

BSP_nameMBX821 002b
NVMEMOne bank 32-bit Flash (2MB, 4MB, or 8MB)
CPU_modelMPC821 40MHZ
SerialTwo additional EIA-232-D serial ports
VideoThe board has an lcd panel connector


Motorola MBX821 002b


MBX821 models include:

  • 40 MHz MPC821 processor;
  • PC/104-Plus; 10BaseT Ethernet;
  • EIDE and Floppy interfaces;
  • 32KB NVRAM;
  • keyboard, mouse, IR, COM1 and COM2 ports;
  • LCD panel connector


MBX821 models include 40 MHz MPC821 processor. The MPC821 processor is especially well-suited for applications where lower power is essential, such as portable and/or high-performance communications systems. The CPU on the MPC821 is a 32-bit PowerPC implementation incorporating memory management units (MMUs) and instruction/data caches. It has a real-time clock and a communications processor module that includes serial communication controllers, serial management controllers, a serial peripheral interface (SPI) channel, and an Interprocessor-Integrated Controller (I2C) channel for data exchanges between the MPC821 and other ICs with I2C capability. The MPC821’s memory controller supports all available types of memory. Its PCMCIA controller supports up to two PCMCIA devices (one socket is provided on the MBX). The MPC821 also incorporates an LCD controller for display capability.


The MBX821-002b has 4MB of DRAM, soldered in place. The MBX series embedded controller has provision for either 4MB or 16MB of on-board DRAM, soldered in place. In addition, it accommodates 8MB to 128MB of expansion DRAM in a 168-pin DIMM (dual in-line memory module) socket, XU3. The on-board DRAM is composed of two 16-bit devices (either 1M x 16 or 4M x 16). Parity protection is optional

Flash Memory

Flash memory on the MBX821-002b embedded controller consists of 4MB. Flash memory on the MBX series embedded controller consists of 2MB, 4MB, or 8MB of memory in one bank of four devices soldered directly to the board. The EPPCBug firmware resident in Flash memory is originally loaded at the factory, but the Flash contents can be reprogrammed if necessary.


  • Serial I/O - EIA-232-D serial console or terminal port (DCE/DTE)
  • Parallel I/O - IEEE 1284 parallel port with host/peripheral mode selection
  • Ethernet I/O - Support for AUI and 10BaseT Ethernet interface
  • PCMCIA interface - One PCMCIA slot (type I, II, or III devices)
  • LCD interface (MPC821 only) - Support for both active and passive LCD panels via 24-pin header on MPC821-powered MBX boards
  • Floppy disk controller - Support for direct ribbon cable connection to 2.88MB floppy disk drive via header on MBX board
  • Keyboard/mouse interface - Support for keyboard and mouse input via header on MBX board


The MBX821-001 embedded controller accommodates 32KB of non- volatile RAM (NVRAM). The MBX series embedded controller accommodates 32KB of Non-Volatile RAM (NVRAM) in a 34-pin socket, XU2. A battery within the device supplies VCC to the NVRAM when main power is removed. The NVRAM provides for a low-battery indication which can be read by the processor. The first 4K of the NVRAM contains the vital product data (VPD) and should not be used. The remaining NVRAM is available for general use.


MBX series embedded controllers can use 3.0V–3.6V battery power (either on board, or external via utility connector #1) as a backup power source for the “keep-alive” power circuits (such as the real-time clock) in the processor. The lifetime of the battery is very dependent on the ambient temperature of the board and the power-on duty cycle. At 70° C, the worst-case elapsed time for battery protection is four years. Battery warning time is 24 hours minimum. At lower ambient temperatures the backup time is greatly extended. When a board is stored, the on-board battery should be disconnected to prolong battery life. This is especially important at high ambient temperatures.

Block diagram

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Last modified on 11/07/18 at 13:41:39 Last modified on 11/07/18 13:41:39